Recently there have been rumors about a possible new Sonic & All-Stars Racing title being in development. Apparently placeholder Sonic & All-Stars Racing Transformed toys were featured at a recent toy event which stated there was a new racing game coming out this year. Supposed slides from a Sumo Digital presentation also leaked:
This was also posted by the same person who leaked information on Sonic Forces in advance (staff checked IP to confirm this isn't an imposter):
Keep in mind these are all just rumors. Nothing has been confirmed yet.